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I can get a 02 JDM STI complete engine minus the ecu and wiring harness for next to nothing. My question is, can I throw this engine in my 02 wrx and run it with my factory ecu and wiring harness, I do have UTEC also.

I have been searching and can't find exactly what I want to know. So I would greatly appreciate some guidance or a redirect to the proper forum/thread. Thanks

Factory ECU, possibly. That motor has AVCS, you need a JDM WRX ECU (at minimum) to run AVCS. I'm not sure what were to happen if you don't have AVCS hooked up and ran a WRX ECU. I'm GUESSING if you had a WRX ECU tuned properly and AVCS unhooked, you would be ok, but don't quote me on that.

Wiring harness is not a big issue since the motor will drop in and plug in with out an issue. you will just need to buy an AVCS wiring kit so that AVCS will work.

I would honestly buy the AVCS wiring kit and the JDM ECU and go to town.

You'll be fine. Everything plugs in. The only difference between the JDM V7 wiring and the USDM WRX wiring is the extra wires for AVCS, which IAP makes a kit where you just repin some of the connectors on the WRX harness to get the AVCS working.

Like Moss said, AVCS won't work with the WRX ECU. It will run fine with no AVCS, the turbo will just lag a bit more than it should. You'll likely feel boost come on around 3000-3300 RPM rather than earlier.

However, you will need a bit of tuning. The WRX ECU can run the V7 motor properly, but you'll have to rescale your injector duty cycle (You can do this via the UTEC, if you don't rescale them the car will barely run, it might not even start) and you'll probably want to tweak the base map a bit to deal with the VF30 turbo, since the WRX ECU is tuned for the TD04. This is actually exactly what I do to get through emissions. You'll also have a bunch of CEL codes, mostly for TGV's since JDM STI motors don't have them, and a CEL for having no EGT probe in the up pipe.

I'll make the suggestion Moss made though, in that you'd be better off getting the IAP AVCS wiring kit (runs about $160) and the JDM ECU (anywhere from $200-450, depending on who/where you buy it from). That way you don't have to do any tuning and your AVCS will function properly.

Ok can you guys tell me what the AVCS is, also my UTEC is tuned for the VF39, 550 STI pinks, FMIC, TBE, Short ram w/K&N, header/up-pipe, walbaro 255 will that make a difference.

So if I get JDM wiring harness and computer is it OBD2 compliant, I was told 02-03 is Japan went to the OBD2 system. Would my UTEC be able piggy back the JDM ECU? JDM are tuned on a lot higher octane are they not.

You only need the AVCS wiring kit, you do NOT need a JDM wiring harness.

Yes, the V7 went to OBD2 however as far as I know, if you're asking about OBD2 compliance for NYS...the NYS Scanner won't read the ECU, or will cause an error.

I have a V7 STi swap in my RS, and I'm from NY(car is still registered and insured in NY even though I'm in MD now). I have yet to have the car inspected in NY because as far as I know, it will not pass the OBD2 scan.

The UTEC tune should be sufficient, assuming you're transferring all those mods over to the V7. You'll want to bump the rev limiter up to 8k though on the UTEC, since its likely set for 7250 for the WRX. The VF39 isn't that far off from the VF30 anyway, but if you want perfection, get a new tune. It will run on that map, but it probably won't be as smooth as it could be. A buddy of mine used to also have a V7 in his car, and he ran a VF22 map with the VF30. It started to break up at WOT though on the track.

Yes, V7 is OBDII, and like I said, the wiring harnesses are identical between the WRX and V7, save for a few extra wires that are on the V7 harness that are not on the WRX for the AVCS (which the kit I suggested you buy adds those wires into the WRX harness). Since the harnesses are virtually identical, this means the WRX and V7 ECU are both plug-and-play. They have the same plugs, and both plug into your WRX harness. If you understand this all correctly, you don't even need the JDM wiring harness.

Japanese Subarus went to OBDII in 2001, the year the V7 was introduced. Anything 2000 and older is all OBDI.

I don't know why a lot of people have not figured this out yet, but for NYS emissions, which are very similar to CT emissions, all you have to do is plop in the WRX ECU to pass emissions, so long as you flash out the CEL codes that would pop up from doing so and mess with some timing and fueling. All this can be done via Opensource tuning. The WRX ECU will satisfy all the emissions parameters that OBDII scanners at emissions testing facilities will look for.

Yes, the V7 runs higher octane, but the ECU, just like any other JDM Subaru ECU, and any Subaru ECU for that matter, can adjust itself to crappier octane. The fact that JDM motors can't run without 96RON is nothing but a MYTH that has been rumored around this board for a long time. So yes, a V7 will run on 93 octane without any tuning. You would not want to throw 87 or pure crap into your gas tank though.

Yes, the UTEC will piggyback the V7 ECU. I ran my car the same way for over a year until I got rid of my UTEC altogether in favor of a reflash.

Depending on whether you have a newer UTEC or older UTEC, if you want the AVCS to work when piggbacking on the V7 ECU, the newer UTEC's have the additional wiring in them already for AVCS, while the older UTEC's do not have this wiring already, so you will have to add the AVCS wires straight into the UTEC, as opposed to straight into the ECU. But don't let this confuse you. Get the car running first and then we can worry about that after.

Depending on whether you have a newer UTEC or older UTEC, if you want the AVCS to work when piggbacking on the V7 ECU, the newer UTEC's have the additional wiring in them already for AVCS, while the older UTEC's do not have this wiring already, so you will have to add the AVCS wires straight into the UTEC, as opposed to straight into the ECU. But don't let this confuse you. Get the car running first and then we can worry about that after.

So if I understand you correctly I do not have to wire the AVCS at all if I have a newer UTEC with these capabilities. If it is and older one then I will have to wire the AVCS to the UTEC instead of the JDM ECU.

Will my UTEC manual tell me if it is AVCS capable, if not how do I found out.

So if I understand you correctly I do not have to wire the AVCS at all if I have a newer UTEC with these capabilities. If it is and older one then I will have to wire the AVCS to the UTEC instead of the JDM ECU.

Will my UTEC manual tell me if it is AVCS capable, if not how do I found out.

No, you still have to wire the AVCS when using a UTEC, regardless of its age. However, on the Newer UTEC you would wire the AVCS wires directly into the stock ECU plugs (since the wires connecting the ECU to the UTEC itself... the bridging wires I guess you would call them, already have the additional wires needed for the AVCS built into them, so in essence you would not be cutting off the signal from ECU to motor's AVCS sensors since the newer UTEC's wiring bridge already has those wires to complete the signal.

However, on older UTEC's this additional wiring for AVCS in the UTEC's wiring bridge is not there. Therefore, you must wire the AVCS wiring kit directly into the bridge itself where the UTEC plugs into the stock ECU. Essentially you are completely bypassing the UTEC's wiring bridge (again, I mean the UTEC's wiring itself where that wiring plugs into the ECU) for the AVCS and connecting the ECU directly to the AVCS sensors.

WRX-based UTEC's don't control AVCS. That's the important thing to know.

It's very hard to explain in words what I'm trying to tell you.

I also don't know the difference between an older and a newer UTEC unless I put them side by side. The UTEC itself are identical, there are just some additional wires in the wiring bridge on the newer one. The reason I know this is my friend that used to have a V7 had a newer UTEC, whereas I had an older UTEC without the additional wires in the UTEC.

When I say "wiring bridge", I'm talking about the green, black and purple wires (I think those are the colors Turbo-XS uses?) that connect the ECU to the UTEC. On older UTEC's you have to wire the AVCS wires directly into the plugs that go into the ECU itself from the UTEC, basicall bypassing the UTEC as far as those go, since there are no purple/green/black wires that correspond to AVCS. In newer UTEC's the additional wiring is there, so the UTEC allows the AVCS signal to go through the UTEC (again, the UTEC doesn't control AVCS, but lets the signal pass through it), so you would wire the kit into the stock white plugs.

I don't know why a lot of people have not figured this out yet, but for NYS emissions, which are very similar to CT emissions, all you have to do is plop in the WRX ECU to pass emissions, so long as you flash out the CEL codes that would pop up from doing so and mess with some timing and fueling. All this can be done via Opensource tuning. The WRX ECU will satisfy all the emissions parameters that OBDII scanners at emissions testing facilities will look for.

As said here, you can run that motor off the US ECU but you will definately need to tune it. If you look a page or so back in here I outlined the steps I went through to safely pass emissions. The motor really is sluggish without the AVCS, its a night and day difference below 4K rpms. I didnt take the car over that with the US to comment on the higher revs.

Sell the UTEC and buy a JDM ECU and IAperformance wiring harness. Get an OpenECU tune and have your tuner flash the tune on both ECUs, when you want to pass emissions swap in the US ecu and drive around for 300-400 miles and then you'll pass. Swap the JDM one back in for AVCS power and you're good for another year.

Sell the UTEC and buy a JDM ECU and IAperformance wiring harness. Get an OpenECU tune and have your tuner flash the tune on both ECUs, when you want to pass emissions swap in the US ecu and drive around for 300-400 miles and then you'll pass. Swap the JDM one back in for AVCS power and you're good for another year.

Ding ding ding! Could not have said it better. Although simply flashing the tune onto the WRX ECU also would require getting rid of some of the CEL's that would come up from using the WRX ECU on the JDM motor, such as TGV's, EGT, etc. Not a big deal if you're using OpenECU though.

Sell the VF30 and get a VF22. There wont be that big of a difference between the 30 and the 39. If you could swing it a big TD06-18G seems like a good match to a jdm motor since you'll keep a bunch of topend. With AVCS you can spool turbos pretty damn quick.

hey im in lowville and when you do the swap i have the taxtic connector to reflash the wrx ecu if you can find a ver 7 stock map values. ive ben tuning with a wideband O2 sensor for myself, friends ect.. but not good enough to tune for customers.. i've also done a few swaps (mostly gc8 ver motr/trans) out of my garage (small time bussiness) so if your looking for someone to do the swap or just need some help let me know. ive got alot of time wrenching on Rue's ive probably seen ya around, ive got a 02 silver wrx with a loud custom exshaust (oh did i mention i build custom stainless exshausts...). anywho let me know...
later
jeff

should be no problem, just by-pass the adjustable intake cam timing by not using it. but is only temporary, at some point soon the ecu will need to be slightly remapped for the different compression characteristics and cam profile. (at least if youd like the motor to run half way decent ). if you don't fully understand, do some more research before diving head first into a big conversion like this. otherwise you can get into big problems..